rmgroup.pl: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/lib/news/bin/control/rmgroup.pl - from package: inn2

You may install the required package with command apt-get install {package}
Error in other languages:
rmgroup.pl: bevel nie gevind nie
rmgroup.pl: comandă negăsită
rmgroup.pl: comando não encontrado
rmgroup.pl: commande introuvable
rmgroup.pl: command not found
rmgroup.pl: käsku ei ole
rmgroup.pl: không tìm thấy lệnh
rmgroup.pl: komanda nerasta
rmgroup.pl: Kommando nicht gefunden.
rmgroup.pl: kommandot finns inte
rmgroup.pl: komut yok
rmgroup.pl: nie znaleziono polecenia
rmgroup.pl: níor aimsíodh an t-ordú
rmgroup.pl: no se encontró la orden
rmgroup.pl: no s'ha trobat l'ordre
rmgroup.pl: opdracht niet gevonden
rmgroup.pl: parancs nem található
rmgroup.pl: perintah tidak ditemukan
rmgroup.pl: príkaz nenájdený
rmgroup.pl: příkaz nenalezen
rmgroup.pl: команда не найдена
rmgroup.pl: командата не е открита
rmgroup.pl: 命令找不到
rmgroup.pl: コマンドが見つかりません